Just released Mesa 7.10.1
Official Ubuntu 10.10 Xorg
Linux 2.6.36-02063603-generic
In some areas of Lightsmark 2008 benchmark fps is not as good as older more stable Mesa versions such as Mesa 7.7.1, 7.8.3-rc1, 7.9-series.
some like half fps.

Three major bugs for Mesa 7.10.1, kicking me back to stay with Mesa 7.8.3-rc1
Bug 32949 - cannot play Windows games with WINE with GLSL enabled
This bug itself - which I guess has performance impact on other games
Bug 33926 - I do not know other Linux native games are affected by this bug

And please include the actual measurements.
commit d1fc920f613aa349e6721963e22e12c6eb49e3f9
Author: Kenneth Graunke <kenneth@whitecape.org>
Date: Tue Mar 1 11:15:34 2011 -0800
intel: Support glCopyTexImage() from ARGB8888 to XRGB8888.
Nexuiz was hitting a software fallback.
also fixes a fallback that Lightsmark was hitting. And Lightsmark is also sensitive to libgomp.so, so make sure you are using the same version of the compiler whilst comparing.

still low at beginning and other areas as well, like before with patched Mesa 7.10.1.
but I do not know about libgomp.so, which version I have to use and how to compare. I did not compile libgomp.so, it comes with Ubuntu 10.10.

commit 615117ce4efd041459f7d4b0c77aa8e248345e66
Author: Eric Anholt <eric@anholt.net>
Date: Mon May 23 09:12:07 2011 -0700
i965/fs: Track fixed GRF regs separate from allocated GRF file in scheduling.
There's an assumption here that fixed GRFs will never intersect with
the allocated GRFs. That's true today, though it might change some
day if we decide to register-allocate the regs containing push
constants once they're dead.
This fixes a regression in 0f7325b89038937bd428f7c89ed9859189a0ab0b in
Lightsmark from the texture instructions now containing g0 references
instead of having that be implied. Performance is improved 15.2% +/-
3.6% (n=3).
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=34968